Field of the Invention
[0001] The present invention relates to liquid cleaning microemulsion composition having
improved foam collapse properties.
Background of the Invention
[0002] This invention relates to an improved all-purpose liquid cleaning composition or
a microemulsion composition having improved foam collapse properties designed in particular
for cleaning hard surfaces and which is effective in removing grease soil and/or bath
soil and in leaving unrinsed surfaces with a shiny appearance.
[0003] In recent years all-purpose liquid detergents have become widely accepted for cleaning
hard surfaces, e.g., painted woodwork and panels, tiled wails, wash bowls, bathtubs,
linoleum or tile floors, washable wall paper, etc. Such all-purpose liquids comprise
clear and opaque aqueous mixtures of water-soluble synthetic organic detergents and
water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency
with granular or powdered all-purpose cleaning compositions, use of water-soluble
inorganic phosphate builder salts was favored in the prior art all-purpose liquids.
For example, such early phosphate-containing compositions are described in U.S. Patent
Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No. 1,223,739.
[0004] In view of the environmentalist's efforts to reduce phosphate levels in ground water,
improved all-purpose liquids containing reduced concentrations of inorganic phosphate
builder salts or non-phosphate builder salts have appeared. A particularly useful
self-opacified liquid of the latter type is described in U.S. Patent No. 4,244,840.
[0005] However, these prior art all-purpose liquid detergents containing detergent builder
salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed
surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing
of the cleaned surfaces which is a time-consuming chore for the user.
[0006] In order to overcome the foregoing disadvantage of the prior art all-purpose liquid,
U.S. Patent No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced
concentration of inorganic phosphate builder salt should be employed. However, such
compositions are not completely acceptable from an environmental point of view based
upon the phosphate content. On the other hand, another alternative to achieving phosphate-free
all-purpose liquids has been to use a major proportion of a mixture of anionic and
nonionic detergents with minor amounts of glycol ether solvent and organic amine as
shown in U.S. Patent No. 3,935,130. Again, this approach has not been completely satisfactory
and the high levels of organic detergents necessary to achieve cleaning cause foaming
which, in turn, leads to the need for thorough rinsing which has been found to be
undesirable to today's consumers.
[0007] Another approach to formulating hard surfaced or all-purpose liquid detergent composition
where product homogeneity and clarity are important considerations involves the formation
of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent
compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and
a "cosurfactant" compound which provides product stability. By definition, an o/w
microemulsion is a spontaneously forming colloidal dispersion of "oil" phase particles
having a particle size in the range of 25 to 800 Å in a continuous aqueous phase.
[0008] In view of the extremely fine particle size of the dispersed oil phase particles,
microemulsions are transparent to light and are clear and usually highly stable against
phase separation.
[0009] Patent disclosures relating to use of grease-removal solvents in o/w microemulsions
include, for example, European Patent Applications EP 0137615 and EP 0137616 - Herbots
et al; European Patent Application EP 0160762 - Johnston et al; and U.S. Patent No.
4,561,991 - Herbots et al. Each of these patent disclosures also teaches using at
least 5% by weight of grease-removal solvent.
[0010] It also is known from British Patent Application GB 2144763A to Herbots et al, published
March 13, 1985, that magnesium salts enhance grease-removal performance of organic
grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent
compositions. The compositions of this invention described by Herbots et al. require
at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably
at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent
with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
[0011] However, since the amount of water immiscible and sparingly soluble components which
can be present in an o/w microemulsion, with low total active ingredients without
impairing the stability of the microemulsion is rather limited (for example, up to
18% by weight of the aqueous phase), the presence of such high quantities of grease-removal
solvent tend to reduce the total amount of greasy or oily soils which can be taken
up by and into the microemulsion without causing phase separation.
[0012] The following representative prior art patents also relate to liquid detergent cleaning
compositions in the form of o/w microemulsions: U.S. Patents No. 4,472,291 - Rosario;
U.S. Patent No. 4,540,448 - Gauteer et al; U.S. Patent No. 3,723,330 - Sheflin; etc.
[0013] EP0347110 teaches an all purpose cleaning composition having a low profile but fails
to teach a composition containing an ethoxylated polyhydric alcohol wherein the composition
exhibits a grease release effect.
[0014] Liquid detergent compositions which include terpenes, such as d-limonene, or other
grease-removal solvent, although not disclosed to be in the form of o/w microemulsions,
are the subject matter of the following representative patent documents: European
Patent Application 0080749; British Patent Specification 1,603,047; and U.S. Patent
Nos. 4,414,128 and 4,540,505. For example, U.S. Patent No. 4,414,128 broadly discloses
an aqueous liquid detergent composition characterized by, by weight:
(a) from 1% to 20% of a synthetic anionic, nonionic, amphoteric or zwitterionic surfactant
or mixture thereof;
(b) from 0.5% to 10% of a mono- or sesquiterpene or mixture thereof, at a weight ratio
of (a):(b) being in the range of 5:1 to 1:3; and
(c ) from 0.5% 10% of a polar solvent having a solubility in water at 15°C in the
range of from 0.2% to 10%. Other ingredients present in the formulations disclosed
in this patent include from 0.05% to 2% by weight of an alkali metal, ammonium or
alkanolammonium soap of a C13-C24 fatty acid; a calcium sequestrant from 0.5% to 13% by weight; non-aqueous solvent,
e.g., alcohols and glycol ethers, up to 10% by weight; and hydrotropes, e.g., urea,
ethanolamines, salts of lower alkylaryl sulfonates, up to 10% by weight. All of the
formulations shown in the Examples of this patent include relatively large amounts
of detergent builder salts which are detrimental to surface shine.
Summary of the Invention
[0015] The present invention provides an improved, liquid cleaning composition having improved
foam collapse properties in the form of a microemulsion which is suitable for cleaning
hard surfaces such as plastic, vitreous and metal surfaces having a shiny finish,
oil stained floors, automotive engines and other engines. More particularly, the improved
cleaning compositions, with improved foam collapse properties exhibit good grease
soil removal properties due to the improved interfacial tensions, when used in undiluted
(neat) form and leave the cleaned surfaces shiny without the need of or requiring
only minimal additional rinsing or wiping. The latter characteristic is evidenced
by little or no visible residues on the unrinsed cleaned surfaces and, accordingly,
overcomes one of the disadvantages of prior art products.
[0016] Surprisingly, these desirable results are accomplished even in the absence of polyphosphate
or other inorganic or organic detergent builder salts and also in the complete absence
or substantially complete absence of grease-removal solvent.
[0017] In one aspect, the invention generally provides a stable, optically clear microemulsion,
hard surface cleaning composition especially effective in the removal of oily and
greasy oil, which is in the form of a substantially dilute oil-in-water microemulsion
having an aqueous phase and an oil phase; The dilute microemulsion composition includes,
on a weight basis:
0.1% to 20% of an anionic surfactant;
0 to 10% of an ethoxylated polyhydric alcohol type compound;
0.1% to 10% of an ethoxylated/propoxylated nonionic surfactant;
0.1% to 15% of a cosurfactant;
0 to 15% of magnesium sulfate heptahydrate;
0.05% to 2% of a fatty acid;
0.1% to 10.0% of a perfume, essential oil, or water insoluble hydrocarbon having 6
to 18 carbon atoms; and
the balance being water.
[0018] In a second aspect, the invention comprises an all purpose hard surface cleaning
composition comprising approximately by weight:
0.1% to 20% of an anionic surfactant;
0.1% to 10% of an ethoxylated/propoxylated nonionic surfactant;
0 to 10% of an ethoxylated polyhydric alcohol type compound;
0.05% to 2% of a fatty acid;
0 to 15% of magnesium sulfate heptahydrate;
0 to 10%, more preferably 0.1% to 10% of a perfume, essential oil or water insoluble
hydrocarbon having 6 to 18 carbon atoms; and
the balance being water.
[0019] The instant compositions do not contain nonionic surfactants formed from the condensation
of a fatty alcohol or phenol type compound with only ethylene oxide.
Detailed Description of the Invention
[0020] The present invention relates to a stable optically clear microemulsion composition
comprising approximately by weight: 0.1% to 20% of an anionic surfactant, 0.05% to
2% of a fatty acid; 0 to 15% of magnesium sulfate heptahydrate; 0.1 % to 10% of a
0.1 % to 10% of an ethoxylated/propylated nonionic surfactant; 0 to 10% of an ethoxylated
polyhydric alcohol type compound; 0 to 10% of a water insoluble hydrocarbon, essential
oil or a perfume and the balance being water.
[0021] The present invention also relates to all purpose hard surface cleaning composition
comprising approximately by weight 0.1% to 20% of an anionic; 0.1% to 10% of an ethoxylated/propoxylated
nonionic surfactant; 0.05% to 2% of a fatty acid; 0 to 15% of magnesium sulfate heptahydrate,
0 to 10%, more preferably 0.4 to 10% of a perfume, essential oil or water insoluble
hydrocarbon having 6 to 18 carbon atoms and the balance being water.
[0022] According to the present invention, the role of the water insoluble hydrocarbon can
be provided by a non-water-soluble perfume Typically, in aqueous based compositions
the presence of a solubilizers, such as alkali metal lower alkyl aryl sulfonate hydrotrope,
triethanolamine, urea, etc., is required for perfume dissolution, especially at perfume
levels of 1% and higher, since perfumes are generally a mixture of fragrant essential
oils and aromatic compounds which are generally not water-soluble. Therefore, by incorporating
the perfume into the aqueous cleaning composition as the oil (hydrocarbon) phase of
the ultimate o/w microemulsion composition, several different important advantages
are achieved.
[0023] As used herein and in the appended claims the term "perfume" is used in its ordinary
sense to refer to and include any non-water soluble fragrant substance or mixture
of substances including natural (i.e., obtained by extraction of flower, herb, blossom
or plant), artificial (i.e., mixture of natural oils or oil constituents) and synthetically
produced substance) odoriferous substances. Typically, perfumes are complex mixtures
of blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic
compounds and varying amounts of essential oils (e.g., terpenes) such as from 0% to
80%, usually from 10% to 70% by weight, the essential oils themselves being volatile
odoriferous compounds and also serving to dissolve the other components of the perfume.
[0024] In the present invention the precise composition of the perfume is of no particular
consequence to cleaning performance so long as it meets the criteria of water immiscibility
and having a pleasing odor. Naturally, of course, especially for cleaning compositions
intended for use in the home, the perfume, as well as all other ingredients, should
be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc.. The instant compositions
show a marked improvement in ecotoxocity as compared to existing commercial products.
[0025] The hydrocarbon such as a perfume is present in the dilute o/w microemulsion in an
amount of from 0 to 10% by weight, preferably from 0.4% to 10% by weight, especially
preferably from 0.5% to 6% by weight. If the amount of hydrocarbon (perfume) is less
than 0.4% by weight it becomes difficult to form the o/w microemulsion. If the hydrocarbon
(perfume) is added in amounts more than 10% by weight, the cost is increased without
any additional cleaning benefit and, in fact, with some diminishing of cleaning performance
insofar as the total amount of greasy or oily soil which can be taken up in the oil
phase of the microemulsion will decrease proportionately. In the all purpose hard
surface cleaning composition which is not a microemulsion the concentration of the
perfume is 0 to 10 wt. %, more preferably 0.1 wt. % to 10 wt. %
[0026] In place of the perfume in either the microemulsion composition or the all purpose
hard surface cleaning composition at the same previously defined concentrations that
the perfume was used in either the microemulsion or the all purpose hard surface cleaning
composition one can employ an essential oil or a water insoluble hydrocarbon having
6 to 18 carbon such as a paraffin or isoparaffin.
[0027] Suitable essential oils are selected from the group consisting of: Anethole 20/21
natural, Aniseed oil china star, Aniseed oil globe brand, Balsam (Peru), Basil oil
(India), Black pepper oil, Black pepper oleoresin 40/20, Bois de Rose (Brazil) FOB,
Borneol Flakes (China), Camphor oil, White, Camphor powder synthetic technical, Cananga
oil (Java), Cardamom oil, Cassia oil (China), Cedarwood oil (China) BP, Cinnamon bark
oil, Cinnamon leaf oil, Citronella oil, Clove bud oil, Clove leaf, Coriander (Russia),
Coumarin 69°C (China), Cyclamen Aldehyde, Diphenyl oxide, Ethyl vanilin, Eucalyptol,
Eucalyptus oil, Eucalyptus citriodora, Fennel oil, Geranium oil, Ginger oil, Ginger
oleoresin (India), White grapefruit oil, Guaiacwood oil, Gurjun balsam, Heliotropin,
Isobornyl acetate, Isolongifolene, Juniper berry oil, L-methyl acetate, Lavender oil,
Lemon oil, Lemongrass oil, Lime oil distilled, Litsea Cubeba oil, Longifolene, Menthol
crystals, Methyl cedryl ketone, Methyl chavicol, Methyl salicylate, Musk ambrette,
Musk ketone, Musk xylol, Nutmeg oil, Orange oil, Patchouli oil, Peppermint oil, Phenyl
ethyl alcohol, Pimento berry oil, Pimento leaf oil, Rosalin, Sandalwood oil, Sandenol,
Sage oil, Clary sage, Sassafras oil, Spearmint oil, Spike lavender, Tagetes, Tea tree
oil, Vanilin, Vetyver oil (Java), Wintergreen
[0028] Regarding the anionic surfactant present in the o/w microemulsions any of the conventionally
used water-soluble anionic surfactants or mixtures of said anionic surfactants and
anionic surfactants can be used in this invention. As used herein the term "anionic
surfactant" is intended to refer to the class of anionic and mixed anionic-nonionic
detergents providing detersive action.
[0029] The water-soluble organic surfactant materials which are used in forming the ultimate
o/w microemulsion compositions of this invention may be selected from the group consisting
of water-soluble, non-soap, anionic surfactants mixed with a fatty acid and a partially
esterfied ethoxylated glycerol.
[0030] Suitable water-soluble non-soap, anionic surfactants include those surface-active
or detergent compounds which contain an organic hydrophobic group containing generally
8 to 26 carbon atoms and preferably 10 to 18 carbon atoms in their molecular structure
and at least one water-solubilizing group selected from the group of sulfonate, sulfate
and carboxylate so as to form a water-soluble detergent. Usually, the hydrophobic
group will include or comprise a C
8-C
22 alkyl, alkyl or acyl group. Such surfactants are employed in the form of water-soluble
salts and the salt-forming cation usually is selected from the group consisting of
sodium, potassium, ammonium, magnesium and mono-, di- or tri-C
2-C
3 alkanolammonium, with the sodium, magnesium and ammonium cations again being preferred.
[0031] Examples of suitable sulfonated anionic surfactants are the well known higher alkyl
mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing
from 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain,
C
8-C
15 alkyl toluene sulfonates and C
8-C
15 alkyl phenol sulfonates.
[0032] One preferred sulfonate surfactant is a linear alkyl benzene sulfonate having a high
content of 3- (or higher) phenyl isomers and a correspondingly low content (well below
50%) of 2- (or lower) phenyl isomers, that is, wherein the benzene ring is preferably
attached in large part at the 3 or higher (for example, 4, 5, 6 or 7) position of
the alkyl group and the content of the isomers in which the benzene ring is attached
in the 2 or 1 position is correspondingly low. Particularly preferred materials are
set forth in U.S. Patent 3,320,174.
[0033] Other suitable anionic surfactants are the olefin sulfonates, including long-chain
alkene sulfonates, long-chain hydroxyalkane sulfonates or mixtures of alkene sulfonates
and hydroxyalkane sulfonates. These olefin sulfonate detergents may be prepared in
a known manner by the reaction of sulfur trioxide (SO
3) with long-chain olefins containing 8 to 25, preferably 12 to 21 carbon atoms and
having the formula RCH=CHR
1 where R is a higher alkyl group of 6 to 23 carbons and R
1 is an alkyl group of 1 to 17 carbons or hydrogen to form a mixture of sultones and
alkene sulfonic acids which is then treated to convert the sultones to sulfonates.
Preferred olefin sulfonates contain from 14 to 16 carbon atoms in the R alkyl group
and are obtained by sulfonating an a-olefin.
[0034] Other example of operative anionic surfactants includes sodium dioctyl sulfosuccinate
[di-(2 ethylhexyl) sodium sulfosuccinate being one ] and corresponding dihexyl and
dioctyl esters. The preferred sulfosuccinic acid ester salts are esters of aliphitic
alcohols such as saturated alkanols of 4 to 12 carbon atoms and are normally diesters
of such alkanols. More preferably such are alkali metal salts of the diesters of alcohols
of 6 to 10 carbons atoms and more preferably the diesters will be from octanol, such
as 2 -ethyl hexanol, and the sulfonic acid salt will be the sodium salt.
[0035] Especially preferred anionic sulfonate surfactants are paraffin sulfonates containing
10 to 20, preferably 13 to 17, carbon atoms. Primary paraffin sulfonates are made
by reacting long-chain alpha olefins and bisulfites and paraffin sulfonates having
the sulfonate group distributed along the paraffin chain are shown in U.S. Patents
Nos. 2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.
[0036] Examples of satisfactory anionic sulfate surfactants are the C
8-C
18 alkyl sulfate salts and the ethoxylated C
8-C
18 alkyl ether sulfate salts having the formula R(OC
2H
4)
n OSO
3M wherein n is 1 to 12, preferably 1 to 5, and M is a solubilizing cation selected
from the group consisting of sodium, potassium, ammonium, magnesium and mono-, di-
and triethanol ammonium ions. The alkyl sulfates may be obtained by sulfating the
alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof
and neutralizing the resultant product.
[0037] On the other hand, the ethoxylated alkyl ether sulfates are obtained by sulfating
the condensation product of ethylene oxide with a C
8-C
18 alkanol and neutralizing the resultant product. The alkyl sulfates may be obtained
by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow
or mixtures thereof and neutralizing the resultant product. On the other hand, the
alkyl ether polyethenoxy sulfates are obtained by sulfating the condensation product
of ethylene oxide with a C
8-C
18 alkanol and neutralizing the resultant product. The alkyl ether polyethenoxy sulfates
differ from one another in the number of moles of ethylene oxide reacted with one
mole of alkanol. Preferred alkyl sulfates and preferred alkyl ether polyethenoxy sulfates
contain 10 to 16 carbon atoms in the alkyl group.
[0038] The ethoxylated C
8-C
12 alkylphenyl ether sulfates containing from 2 to 6 moles of ethylene oxide in the
molecule also are suitable for use in the inventive compositions. These surfactants
can be prepared by reacting an alkyl phenol with 2 to 6 moles of ethylene oxide and
sulfating and neutralizing the resultant ethoxylated alkylphenol.
[0039] Other suitable anionic detergents are the C
9-C
15 alkyl ether polyethenoxyl carboxylates having the structural formula R(OC
2H
4)
nOX COOH wherein n is a number from 4 to 12, preferably 5 to 10 and X is selected from
the group consisting of CH
2, C(O)R
1 and
wherein R
1 is a C
1-C
3 alkylene group. Preferred compounds include C
9-C
11 alkyl ether polyethenoxy (7-9) C(O) CH
2CH
2COOH, C
13-C
15 alkyl ether polyethenoxy (7-9)
and C
10-C
12 alkyl ether polyethenoxy (5-7) CH
2COOH. These compounds may be prepared by condensing ethylene oxide with appropriate
alkanol and reacting this reaction product with chloracetic acid to make the ether
carboxylic acids as shown in US Pat. No. 3,741,911 or with succinic anhydride or phtalic
anhydride.
[0040] Obviously, these anionic surfactants will be present either in acid form or salt
form depending upon the pH of the final composition, with the salt forming cation
being the same as for the other anionic detergents.
[0041] Of the foregoing non-soap anionic sulfonate surfactants, the preferred surfactants
are the magnesium salt of the C
13-C
17 paraffin or alkane sulfonates.
[0042] Generally, the proportion of the nonsoap-anionic surfactant will be in the range
of 0.1% to 20.0%, preferably from 1% to 15%, by weight of the dilute o/w microemulsion
composition or the all purpose hard surface cleaning composition.
[0043] The instant composition can contain a composition (herein after referred to as an
ethoxylated polyhydric alcohol type compound such as an ethoxylated glycerol type
compound) which is a mixture of a fully esterified ethoxylated polyhydric alcohol,
a partially esterified ethoxylated polyhydric alcohol and a nonesterified ethoxylated
polyhydric alcohol, wherein the preferred polyhydric alcohol is glycerol, and the
compound is
and
wherein w equals one to four, most preferably one, and B is selected from the group
consisting of hydrogen or a group represented by:
wherein R is selected from the group consisting of alkyl group having 6 to 22 carbon
atoms, more preferably 11 to 15 carbon atoms and alkenyl groups having 6 to 22 carbon
atoms, more preferably 11 to 15 carbon atoms, wherein a hydrogenated tallow alkyl
chain or a coco alkyl chain is most preferred, wherein at least one of the B groups
is represented by said
and R' is selected from the group consisting of hydrogen and methyl groups; x, y
and z have a value between 0 and 60, more preferably 0 to 40, provided that (x+y+z)
equals 2 to 100, preferably 4 to 24 and most preferably 4 to 19, wherein in Formula
(I) the weight ratio of monoester / diester / triester is 40 to 90 / 5 to 35 / 1 to
20, more preferably 50 to 90 / 9 to 32 / 1 to 12, wherein the weight ratio of Formula
(I) to Formula (II) is a value between 3 to 0.02, preferably 3 to 0.1, most preferably
1.5 to 0.2, wherein it is most preferred that there is more of Formula (II) than Formula
(I) in the mixture that forms the compound.
[0044] The ethoxylated glycerol type compound used in the instant composition is manufactured
by the Kao Corporation and sold under the trade name Levenol such as Levenol F-200
which has an average EO of 6 and a molar ratio of coco fatty acid to glycerol of 0.55
or Levenol V501/2 which has an average EO of 17 and a molar ratio of tallow fatty
acid to glycerol of 1.0. It is preferred that the molar ratio of the fatty acid to
glycerol is less than 1.7, more preferably less than 1.5 and most preferably less
than 1.0. The ethoxylated glycerol type compound has a molecular weight of 400 to
1600, and a pH (50 grams / liter of water) of 5-7. The Levenol compounds are substantially
non irritant to human skin and have a primary biodegradabillity higher than 90% as
measured by the Wickbold method Bias-7d.
[0045] Two examples of the Levenol compounds are Levenol V-501/2 which has 17 ethoxylated
groups and is derived from tallow fatty acid with a fatty acid to glycerol ratio of
1.0 and a molecular weight of 1465 and Levenol F-200 has 6 ethoxylated groups and
is derived from coco fatty acid with a fatty acid to glycerol ratio of 0.55. Both
Levenol F-200 and Levenol V-501/2 are composed of a mixture of Formula (I) and Formula
(II). The Levenol compounds has ecoxicity values of algae growth inhibition > 100
mg/liter; acute toxicity for Daphniae > 100 mg/liter and acute fish toxicity > 100
mg/liter. The Levenol compounds have a ready biodegradability higher than 60% which
is the minimum required value according to OECD 301 B measurement to be acceptably
biodegradable.
[0046] Polyesterified nonionic compounds also useful in the instant compositions are Crovol
PK-40 and Crovol PK-70 manufactured by Croda GMBH of the Netherlands. Crovol PK-40
is a polyoxyethylene (12) Palm Kernel Glyceride which has 12 EO groups. Crovol PK-70
which is preferred is a polyoxyethylene (45) Palm Kernel Glyceride have 45 EO groups.
[0047] The water soluble nonionic surfactants which can be utilized in this invention are
an aliphatic ethoxylated/propoxylated nonionic surfactants which are depicted by the
formula:
or
wherein R is a branched chain alkyl group having about 10 to about 16 carbon atoms,
preferably an isotridecyl group and x and y are independently numbered from 1 to 20.
A preferred ethoxylated/propoxylated nonionic surfactant is Plurafac® 300 manufactured
by BASF.
[0048] The major class of compounds found to provide highly suitable cosurfactants for the
microemulsion over temperature ranges extending from 5°C to 43°C for instance are
water-soluble polyethylene glycols having a molecular weight of 150 to 1000, polypropylene
glycol of the formula HO(CH
3CHCH
2O)
nH wherein n is a number from 2 to 18, mixtures of polyethylene glycol and polypropylene
glycol (Synalox) and mono and di C
1-C
6 alkyl ethers and esters of ethylene glycol and propylene glycol having the structural
formulas R(X)
nOH, R
1(X)
nOH, R(X)
nOR and R
1(X)
nOR
1wherein R is C
1- C
6 alkyl group, R
1 is C
2-C
4 acyl group, X is (OCH
2CH
2) or (OCH
2(CH
3)CH) and n is a number from 1 to 4, diethylene glycol, triethylene glycol, an alkyl
lactate, wherein the alkyl group has 1 to 6 carbon atoms, 1methoxy-2-propanol, 1methoxy-3-propanol,
and 1methoxy 2-, 3- or 4-butanol.
[0049] Representative members of the polypropylene glycol include dipropylene glycol and
polypropylene glycol having a molecular weight of 150 to 1000, e.g., polypropylene
glycol 400. Other satisfactory glycol ethers are ethylene glycol monobutyl ether (butyl
cellosolve), diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol
monobutyl ether, mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol
monobutyl ether, mono, di, tripropylene glycol monomethyl ether, propylene glycol
monomethyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether,
propylene glycol tertiary butyl ether, ethylene glycol monoethyl ether, ethylene glycol
monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopentyl ether,
diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene
glycol monopropyl ether, diethylene glycol monopentyl ether, triethylene glycol monomethyl
ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene
glycol monopentyl ether, triethylene glycol monohexyl ether, mono, di, tripropylene
glycol monoethyl ether, mono, di tripropylene glycol monopropyl ether, mono, di, tripropylene
glycol monopentyl ether, mono, di, tripropylene glycol monohexyl ether, mono, di,
tributylene glycol mono methyl ether, mono, di, tributylene glycol monoethyl ether,
mono, di, tributylene glycol monopropyl ether, mono, di, tributylene glycol monobutyl
ether, mono, di, tributylene glycol monopentyl ether and mono, di, tributylene glycol
monohexyl ether, ethylene glycol monoacetate and dipropylene glycol propionate. When
these glycol type cosurfactants are at a concentartion of about 1.0 to about 14 weight
%, more preferably about 2.0 weight % to about 10 weight % in combination with a water
insoluble hydrocarbon which is at a concentration of at least 0.5 weight %, more preferably
1.5 weight % one can form a microemulsion composition.
[0050] While all of the aforementioned glycol ether compounds provide the described stability,
the most preferred cosurfactant compounds of each type, on the basis of cost and cosmetic
appearance (particularly odor), are dipropylene glycol monomethyl ether and diethylene
glycol monobutyl ether. Other suitable water soluble cosurfactants are water soluble
esters such as ethyl lactate and water soluble carbohydrates such as butyl glycosides.
[0051] The amount of cosurfactant required to stabilize the microemulsion compositions will,
of course, depend on such factors as the surface tension characteristics of the cosurfactant,
the type and amounts of the primary surfactants and water insoluble hydrocarbon, and
the type and amounts of any other additional ingredients which may be present in the
composition and which have an influence on the thermodynamic factors enumerated above.
Generally, amounts of cosurfactant in the range of from 0 to 15%, preferably from
about 0.1 wt. % to 10 wt. % provide stable dilute o/w microemulsions for the above-described
levels of primary surfactants and water insoluble hydrocarbon and any other additional
ingredients as described below.
[0052] The final essential ingredient in the inventive microemulsion compositions or all
purpose hard surface cleaning compositions having improved interfacial tension properties
is water. The proportion of water in the microemulsion or all purpose hard surface
cleaning composition compositions generally is in the range of 20% to 97%, preferably
70% to 97% by weight.
[0053] As believed to have been made clear from the foregoing description, the dilute o/w
microemulsion liquid all-purpose cleaning compositions of this invention are especially
effective when used as is, that is, without further dilution in water, since the properties
of the composition as an o/w microemulsion are best manifested in the neat (undiluted)
form. However, at the same time it should be understood that depending on the levels
of surfactants, cosurfactants, perfume and other ingredients, some degree of dilution
without disrupting the microemulsion, per se, is possible. For example, at the preferred
low levels of active surfactant compounds (i.e., primary anionic and nonionic detergents)
dilutions up to 50% will generally be well tolerated without causing phase separation,
that is, the microemulsion state will be maintained.
[0054] In addition to the above-described essential ingredients required for the formation
of the microemulsion composition, the compositions of this invention may often and
preferably do contain one or more additional ingredients which serve to improve overall
product performance.
[0055] One such ingredient is an inorganic or organic salt of oxide of a multivalent metal
cation, particularly Mg
++. The metal salt or oxide provides several benefits including improved cleaning performance
in dilute usage, particularly in soft water areas, and minimized amounts of perfume
required to obtain the microemulsion state. Magnesium sulfate, either anhydrous or
hydrated (e.g., heptahydrate), is especially preferred as the magnesium salt. Good
results also have been obtained with magnesium oxide, magnesium chloride, magnesium
acetate, magnesium propionate and magnesium hydroxide. These magnesium salts can be
used with formulations at neutral or acidic pH since magnesium hydroxide will not
precipitate at these pH levels.
[0056] Although magnesium is the preferred multivalent metal from which the salts (inclusive
of the oxide and hydroxide) are formed, other polyvalent metal ions also can be used
provided that their salts are nontoxic and are soluble in the aqueous phase of the
system at the desired pH level.
[0057] Thus, depending on such factors as the pH of the system, the nature of the primary
surfactants and cosurfactant, and so on, as well as the availability and cost factors,
other suitable polyvalent metal ions include aluminum, copper, nickel, iron, calcium,
etc. It should be noted, for example, that with the preferred paraffin sulfonate anionic
detergent calcium salts will precipitate and should not be used. It has also been
found that the aluminum salts work best at pH below 5 or when a low level, for example
1 weight percent, of citric acid is added to the composition which is designed to
have a neutral pH. Alternatively, the aluminum salt can be directly added as the citrate
in such case. As the salt, the same general classes of anions as mentioned for the
magnesium salts can be used, such as halide (e.g., bromide, chloride), sulfate, nitrate,
hydroxide, oxide, acetate, propionate, etc.
[0058] Preferably, in the dilute compositions the metal compound is added to the composition
in an amount sufficient to provide at least a stoichiometric equivalent between the
anionic surfactant and the multivalent metal cation. For example, for each gram-ion
of Mg++ there will be 2 gram moles of paraffin sulfonate, alkylbenzene sulfonate,
etc., while for each gram-ion of Al
3+ there will be 3 gram moles of anionic surfactant. Thus, the proportion of the multivalent
salt generally will be selected so that one equivalent of compound will neutralize
from 0.1 to 1.5 equivalents, preferably 0.9 to 1.4 equivalents, of the acid form of
the anionic surfactant. At higher concentrations of anionic surfactant, the amount
of multivalent salt will be in range of 0.5 to 1 equivalents per equivalent of anionic
surfactant.
[0059] The microemulsion compositions can include from 0% to 2.5%, preferably from 0.05%
to 2.0% by weight of the composition of a C
8-C
22 fatty acid or fatty acid soap as a foam suppressant.
[0060] The addition of fatty acid or fatty acid soap provides an improvement in the rinseability
of the composition whether applied in neat or diluted form. Generally, however, it
is necessary to increase the level of cosurfactant to maintain product stability when
the fatty acid or soap is present. If more than 2.5 wt. % of a fatty acid is used
in the instant compositions, the composition will become unstable at low temperatures
as well as having an objectionable smell.
[0061] As example of the fatty acids which can be used as such or in the form of soap, mention
can be made of distilled coconut oil fatty acids, "mixed vegetable" type fatty acids
(e.g. high percent of saturated, mono-and/or polyunsaturated C
18 chains); oleic acid, stearic acid, palmitic acid, eiocosanoic acid, and the like,
generally those fatty acids having from 8 to 22 carbon atoms being acceptable.
[0062] The all-purpose liquid cleaning composition of this invention may, if desired, also
contain other components either to provide additional effect or to make the product
more attractive to the consumer. The following are mentioned by way of example: Colors
or dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1% by weight;
preservatives or antioxidizing agents, such as formalin, 5-bromo-5-nitro-dioxan-1,3;
5-chloro-2-methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts
up to 2% by weight; and pH adjusting agents, such as sulfuric acid or sodium hydroxide,
as needed. Furthermore, if opaque compositions are desired, up to 4% by weight of
an opacifier may be added.
[0063] In final form, the all-purpose hard surface liquid cleaning compositions and clear
microemulsions exhibit stability at reduced and increased temperatures. More specifically,
such compositions remain clear and stable in the range of 4°C to 50°C, especially
2°C to 43°C. Such compositions exhibit a pH in the acid or neutral range depending
on intended end use. The liquids are readily pourable and exhibit a viscosity in the
range of 6 to 60 milliPascal second (mPas.) as measured at 25°C with a Brookfield
RVT Viscometer using a #1 spindle rotating at 20 RPM. Preferably, the viscosity is
maintained in the range of 10 to 40 mPas.
[0064] The compositions are directly ready for use or can be diluted as desired and in either
case no or only minimal rinsing is required and substantially no residue or streaks
are left behind. Furthermore, because the compositions are free of detergent builders
such as alkali metal polyphosphates they are environmentally acceptable and provide
a better "shine" on cleaned hard surfaces.
[0065] When intended for use in the neat form, the liquid compositions can be packaged under
pressure in an aerosol container or in a pump-type sprayer for the so-called spray-and-wipe
type of application.
[0066] Because the compositions as prepared are aqueous liquid formulations and since no
particular mixing is required to form the microemulsion, the compositions are easily
prepared simply by combining all the ingredients in a suitable vessel or container.
The order of mixing the ingredients is not particularly important and generally the
various ingredients can be added sequentially or all at once or in the form of aqueous
solutions of each or all of the primary detergents and cosurfactants can be separately
prepared and combined with each other and with the perfume. The magnesium salt, or
other multivalent metal compound, when present, can be added as an aqueous solution
thereof or can be added directly. It is not necessary to use elevated temperatures
in the formation step and room temperature is sufficient.
[0067] The instant microemulsion formulas explicitly exclude alkali metal silicates and
alkali metal builders such as alkali metal polyphosphates, alkali metal carbonates,
alkali metal phosphonates and alkali metal citrates because these materials, if used
in the instant composition, would cause the composition to have a high pH as well
as leaving residue on the surface being cleaned.
[0068] The following examples illustrate liquid cleaning compositions of the described invention.
Unless otherwise specified, all percentages are by weight. The exemplified compositions
are illustrative only and do not limit the scope of the invention. Unless otherwise
specified, the proportions in the examples and elsewhere in the specification are
by weight.
Example 1
[0069] The following compositions in wt. % were prepared by simple mixing at 25°C:
|
A |
B Ref |
C |
D |
E |
F |
G |
H |
I |
Sodium C13-C17 Paraffin sulfonate |
4.7 |
4.4 |
3.12 |
3.12 |
3.12 |
3.12 |
3.12 |
4 |
4 |
EO/PO nonionic Plurafac® 300 (BASF) |
- |
- |
0.94 |
- |
0.94 |
1.88 |
- |
2.4 |
- |
Levenol F-200 |
2.3 |
2.1 |
0.94 |
0.94 |
0.94 |
- |
- |
- |
|
C13-C15 EO 14 nonionic |
- |
- |
- |
|
- |
- |
|
- |
|
Ethoxylated nonionic (C9-C11 EO: 5) |
- |
- |
- |
0.94 |
- |
- |
1.88 |
- |
2.4 |
DEGMBE |
4 |
4 |
4.75 |
4.75 |
4.75 |
4.75 |
4.75 |
2.8 |
2.8 |
Fatty acid |
0.75 |
0.70 |
0.45 |
0.45 |
0.45 |
0.4 |
0.4 |
0.5 |
0.5 |
MgSO4 7 H2O |
2.2 |
|
1.2 |
1.2 |
1.2 |
1.2 |
1.2 |
1.5 |
1.5 |
Perfume (a) |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
Sodium Citrate |
- |
- |
- |
- |
0.8 |
- |
- |
- |
- |
Water |
Bal |
Bal |
Bal |
Bal |
Bal |
Bal |
Bal |
Bal |
Bal |
pH |
7 |
7 |
7 |
7 |
7 |
7 |
7 |
7 |
7 |
Degreasing test Neat (b) |
20 |
20 |
20 |
20 |
NA |
20 |
20 |
20 |
20 |
Autocativity Dilute |
Equal to ref. |
ref |
SI. Better |
Equal to ref. |
NA |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Residue |
Equal to ref. |
ref. |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Equal to ref. |
Foam collapse |
Equal to ref. |
ref. |
Equal to ref. |
Worse |
Equal to ref. |
Faster |
Worse |
Faster |
Worse |
Aspect |
Clear |
Clear |
Clear |
Clear |
Clear |
Clear |
Clear |
Clear |
2 phases |
(a) contains 25% by weight of terpenes. |
(b) the lower the number of strokes, the better the degreasing performance. |
[0070] In summary, the described invention broadly relates to an improvement in microemulsion
and all purpose hard surface cleaning compositions containing an anionic surfactant,
optionally, a partially esterified ethoxylated polyhydric alcohol, an ethoxylated/propoxylated
nonionic surfactant, a cosurfactant, a fatty acid, a magnesium sulfate, a hydrocarbon
ingredient and water.